And use punctuation when asking things! You will be taken a whole lot more seriously.
There is a way to do it, but as Seventh said, your a bit too much of a learner to go around doing these things. You need a program called 'Wally' which allows you to make your own .wad files (textures), in which you can make your signature, save it as a wad file, and then add into hammer.
If you use Custom Textures, make sure you -wadinclude them (Needs ZHLT Compile Tools [there is a tutorial on this site about how to do wadincludes]) or include the .wad with the map if you submit it.